Festival offers a general framework for building speech synthesis
systems as well as including examples of various modules. As a whole
it offers full text to speech through a number APIs: from shell level,
though a Scheme command interpreter, as a C++ library, from Java, and
an Emacs interface. Festival is multi-lingual (currently English
(British and American), and Spanish) though English is the most
advanced. Other groups release new languages for the system.
And full tools and documentation for build new voices are
available through Carnegie Mellon's FestVox project (http://festvox.org)
The system is written in C++ and uses the Edinburgh Speech Tools
Library for low level architecture and has a Scheme (SIOD) based
command interpreter for control. Documentation is given in the FSF
texinfo format which can generate, a printed manual, info files and
HTML.
Festival is free software. Festival and the speech tools are
distributed under an X11-type licence allowing unrestricted commercial
and non-commercial use alike.

For a summary on how to use the package collection, see the
README.html. robotpkg is designed to
permit easy installation from source - particularly useful if the
latest binary package is not available for your chosen platform.